<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
</html>
<script>
    //强制转换 typeof
    console.log(typeof Number(123));
    console.log(typeof Number("123zc"));
    console.log(typeof Number("123abc"));
    console.log( Number(true));
    console.log( Number(false));
    console.log(Number(""));


    //强型转换 String
    console.log(String("123"));
    console.log(String(true));
    console.log(String(false));

    
    //枪型转换 Boolean
    console.log(Boolean(true));
    console.log(Boolean(false));
    console.log(Boolean("123"));
    console.log(Boolean(null));
</script>